1. Field of the Invention
The present invention relates to an apparatus for increasing field of view of an optical system.
2. Discussion of the Related Art
Generally, Many different types of optical systems such as digital cameras, digital video cameras, image pick-up systems used in cars, and real-time detector systems, are known and have different properties which may be of potential relative advantage in particular applications. However, application of some types of optical systems for purposes in which they might be otherwise advantageous may be precluded by corresponding constraints. As a simple example, large fields of view must generally be provided by wide-angle lenses, which characteristically exhibit substantial distortion that increases with off-axis angle. Correction of such distortion is often only possible with expensive aspheric elements or by using image processing which is expensive. However, it is difficult to achieve a relatively wide angle of view as required to accommodate the size of objects of interest while maintaining the overall system (object, lens, and camera/sensor) at an acceptable size.
What is needed, therefore, is an apparatus for increasing field of view of optical system, which satisfies the needs for performance enhancement, with low distortion.